Shell and tube heat exchangers for exchanging heat between two fluids, a first and second fluid respectively, are already known, whereby the heat exchanger is made up of a housing in which one or more tubes extend that are fastened at their ends to partitions that divide the housing into three compartments, i.e. an inlet compartment and an outlet compartment for the first fluid, and a central compartment between them with its own inlet and outlet for the second fluid.
In conventional shell and tube heat exchangers, one or more baffles are provided transverse to the direction of the tubes and the tubes extend through passages in these baffles in order to guide the flow of the second fluid according to a certain pattern.
Traditionally the baffles are mounted such that a passage is left free for the second fluid, alternately on the one side and the opposite side of the housing, so that the second fluid follows a zigzag pattern.
In the known heat exchangers, the baffles are kept at a distance from one another by fastening means in the form of spacer bushes or spacer plates that are affixed between the baffles.
In the case of spacer bushes, at least one threaded rod is affixed through each series of spacer bushes located in line with one another, all such that these threaded rods also extend through the respective passages in the baffles.
A disadvantage of such a conventional arrangement is that the threaded rods and the spacer bushes must be made of a sufficiently thick material as the movement of the baffles, as a result of the flow of the second fluid through the central compartment, must be limited.
The large quantity of material required of course implies high material costs.
Another disadvantage is that the placement of the baffles is laborious such that the assembly of the tube heat exchanger is labour-intensive and thus expensive.
An alternative is described in EP 2480850 wherein a fastening element in the form of a grooved V-profile is pressed together and snapped into recesses on the periphery of the baffles, more specifically under lips that are affixed at the edges of these recesses.
This has the disadvantage that the squeezing together of these V-shaped profiles requires a substantial force, so that the V-shaped profiles necessarily must be made of relatively thin material, which again has the result that the rigidity of the construction obtained is limited.
At the same time it is not easy to exert a significant force for squeezing the V-shaped profiles together and to accurately manipulate these profiles in order to place them in the recesses in the baffles.